Wet etching method and wet etching apparatus

Abstract

A fine pattern is formed on a surface of a processing object without using photoresist. A wet etching for the processing object in an area to which ultraviolet light is applied is performed by bringing a solution in which nitrous oxide (N 2 O) is dissolved into contact with the processing object and applying the ultraviolet light to the solution in a vicinity of an area to the processing object other than portions shielded with a mask whereupon a light shielding pattern is formed.

1 - 25 . (canceled) 
     
     
         26 . A wet etching method comprising:
 bringing a solution in which nitrous oxide (N 2 O) is dissolved into contact with a processing object; and   by applying ultraviolet light to the solution in an area in which it is in contact, dissolving away the processing object in a vicinity of an area to which the ultraviolet light is applied.   
     
     
         27 . A wet etching method comprising:
 by applying ultraviolet light to a solution in which nitrous oxide (N 2 O) is dissolved to dissociate oxygen, allowing the dissociated oxygen to oxidize a processing object to generate an oxide; and   allowing the generated oxide to dissolve in the solution and be removed.   
     
     
         28 . The wet etching method according to  claim 26 , wherein
 the solution includes nitrous oxide of a concentration in a range from 10 ppm to 5,000 ppm.   
     
     
         29 . The wet etching method according to  claim 27 , wherein
 the solution includes nitrous oxide of a concentration in a range from 10 ppm to 5,000 ppm.   
     
     
         30 . The wet etching method according to  claim 26 , wherein
 the solution includes at least any one of water, methanol, ethanol, isopropanol, methylcyclohexane, cyclohexane, acetonitryl, hexane, dioxane, glycerine, n-pentane, or dichloromethane.   
     
     
         31 . The wet etching method according to  claim 27 , wherein
 the solution includes at least any one of water, methanol, ethanol, isopropanol, methylcyclohexane, cyclohexane, acetonitryl, hexane, dioxane, glycerine, n-pentane, or dichloromethane.   
     
     
         32 . The wet etching method according to  claim 26 , wherein
 the solution is a solution to which an acid or an alkali is added.   
     
     
         33 . The wet etching method according to  claim 27 , wherein
 the solution is a solution to which an acid or an alkali is added.   
     
     
         34 . The wet etching method according to  claim 32 , wherein
 the solution is a solution which includes any acid of sulfuric acid, phosphoric acid, hydrochloric acid, boric acid, carbonic acid, hydrofluoric acid, nitric acid, formic acid, acetic acid or oxalic acid.   
     
     
         35 . The wet etching method according to  claim 33 , wherein
 the solution is a solution which includes any acid of sulfuric acid, phosphoric acid, hydrochloric acid, boric acid, carbonic acid, hydrofluoric acid, nitric acid, formic acid, acetic acid or oxalic acid.   
     
     
         36 . The wet etching method according to  claim 32 , wherein
 the solution is a solution which includes any alkali of ammonia, sodium hydroxide, potassium hydroxide, or tetramethylammonium hydroxide.   
     
     
         37 . The wet etching method according to  claim 33 , wherein
 the solution is a solution which includes any alkali of ammonia, sodium hydroxide, potassium hydroxide, or tetramethylammonium hydroxide.   
     
     
         38 . The wet etching method according to  claim 26 , wherein
 the ultraviolet light is ultraviolet light having a spectrum with a wavelength range of 173 nm to 240 nm.   
     
     
         39 . The wet etching method according to  claim 27 , wherein
 the ultraviolet light is ultraviolet light having a spectrum with a wavelength range of 173 nm to 240 nm.   
     
     
         40 . The wet etching method according to  claim 26 , wherein
 the ultraviolet light is ultraviolet light emitted by a mercury lamp.   
     
     
         41 . The wet etching method according to  claim 27 , wherein
 the ultraviolet light is ultraviolet light emitted by a mercury lamp.   
     
     
         42 . The wet etching method according to  claim 26 , wherein
 the ultraviolet light is ultraviolet light emitted by an excimer lamp.   
     
     
         43 . The wet etching method according to  claim 27 , wherein
 the ultraviolet light is ultraviolet light emitted by an excimer lamp.   
     
     
         44 . The wet etching method according to  claim 26 , wherein
 the processing object is one kind chosen from silicon, aluminium, copper, iron, zinc, titanium, tantalum, silver, zirconium, tungsten, chromium, molybdenum, nickel, hafnium, ruthenium, niobium, yttrium, scandium, neodymium, lanthanum, cerium, cobalt, vanadium, manganese, gallium, germanium, indium, tin, rhodium, palladium, cadmium, antimony, or an alloy including these.   
     
     
         45 . The wet etching method according to  claim 27 , wherein
 the processing object is one kind chosen from silicon, aluminium, copper, iron, zinc, titanium, tantalum, silver, zirconium, tungsten, chromium, molybdenum, nickel, hafnium, ruthenium, niobium, yttrium, scandium, neodymium, lanthanum, cerium, cobalt, vanadium, manganese, gallium, germanium, indium, tin, rhodium, palladium, cadmium, antimony, or an alloy including these.   
     
     
         46 . The wet etching method according to  claim 26 , wherein
 the processing object is a processing substrate wherein a copper film is formed on the substrate.   
     
     
         47 . The wet etching method according to  claim 27 , wherein
 the processing object is a processing substrate wherein a copper film is formed on the substrate.   
     
     
         48 . The wet etching method according to  claim 26 , wherein
 the processing object is a silicon substrate.   
     
     
         49 . The wet etching method according to  claim 27 , wherein
 the processing object is a silicon substrate.   
     
     
         50 . The wet etching method according to  claim 26 , wherein
 the processing object is a processing substrate wherein a molybdenum film is formed on the substrate.   
     
     
         51 . The wet etching method according to  claim 27 , wherein
 the processing object is a processing substrate wherein a molybdenum film is formed on the substrate.   
     
     
         52 . The wet etching method according to  claim 26 , wherein
 the ultraviolet light is locally applied to the solution in a vicinity of the processing object.   
     
     
         53 . The wet etching method according to  claim 27 , wherein
 the ultraviolet light is locally applied to the solution in a vicinity of the processing object.   
     
     
         54 . The wet etching method according to  claim 26 , wherein
 the ultraviolet light is applied to the solution in the vicinity of the processing object except for in portions blocked by a mask.   
     
     
         55 . The wet etching method according to  claim 27 , wherein
 the ultraviolet light is applied to the solution in the vicinity of the processing object except for in portions blocked by a mask.   
     
     
         56 . The wet etching method according to  claim 26 , wherein
 a volume of the processing object dissolved away is controlled by controlling an application time of the ultraviolet light.   
     
     
         57 . The wet etching method according to  claim 27 , wherein
 a volume of the processing object dissolved away is controlled by controlling an application time of the ultraviolet light.   
     
     
         58 . The wet etching method according to  claim 26 , wherein
 a depth to which the processing object is dissolved away is controlled by controlling the application time of the ultraviolet light.   
     
     
         59 . The wet etching method according to  claim 27 , wherein a depth to which the processing object is dissolved away is controlled by controlling the application time of the ultraviolet light. 
     
     
         60 . The wet etching method according to  claim 26 , wherein
 the processing object is brought into contact with the solution by immersing it therein.   
     
     
         61 . The wet etching method according to  claim 27 , wherein
 the processing object is brought into contact with the solution by immersing it therein.   
     
     
         62 . The wet etching method according to  claim 26 , wherein
 the solution is supplied to, and brought into contact with, a surface of the processing object.   
     
     
         63 . The wet etching method according to  claim 27 , wherein
 the solution is supplied to, and brought into contact with, a surface of the processing object.   
     
     
         64 . A wet etching apparatus comprising:
 contact means which brings a solution in which nitrous oxide is dissolved into contact with a processing object; and   light application means which applies ultraviolet light to the solution in an area in which it is in contact, wherein   the apparatus is configured in such a way as to etch the processing object in a vicinity of an area to which the ultraviolet light is applied by the light application means.   
     
     
         65 . The wet etching apparatus according to  claim 64 , wherein the contact means includes:
 solution holding means for holding the solution in which the nitrous oxide is dissolved; and   processing object holding means for holding the processing object, and the light application means includes:   a light source which emits ultraviolet light; and   mask supporting means for interposing a light intercepting mask between the light source and the processing object holding means.   
     
     
         66 . The wet etching apparatus according to  claim 64 , wherein the contact means includes:
 the solution holding means for holding the solution in which the nitrous oxide is dissolved;   the processing object holding means for holding the processing object; and   solution supply means for supplying the solution from the solution holding means to the processing object,   and the light application means includes:   the mask supporting means for interposing the light intercepting mask between the light source and the processing object holding means.   
     
     
         67 . The wet etching apparatus according to  claim 64 , wherein the light application means includes:
 the light source which emits the ultraviolet light; and   optical path adjustment means for applying the emitted ultraviolet light to the processing object.   
     
     
         68 . The wet etching apparatus according to  claim 64 , wherein
 the optical path adjustment means includes a lens made of quartz for collecting the ultraviolet light.